From: Eugen Hristev <eugen.hristev@collabora.com> To: tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, jaegeuk@kernel.org, chao@kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel@collabora.com, eugen.hristev@collabora.com, viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, krisman@suse.de, Gabriel Krisman Bertazi <krisman@collabora.com> Subject: [PATCH v14 3/9] libfs: Introduce case-insensitive string comparison helper Date: Wed, 20 Mar 2024 10:46:16 +0200 [thread overview] Message-ID: <20240320084622.46643-4-eugen.hristev@collabora.com> (raw) In-Reply-To: <20240320084622.46643-1-eugen.hristev@collabora.com> From: Gabriel Krisman Bertazi <krisman@collabora.com> generic_ci_match can be used by case-insensitive filesystems to compare strings under lookup with dirents in a case-insensitive way. This function is currently reimplemented by each filesystem supporting casefolding, so this reduces code duplication in filesystem-specific code. Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> [eugen.hristev@collabora.com: rework to first test the exact match] Signed-off-by: Eugen Hristev <eugen.hristev@collabora.com> --- fs/libfs.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/fs.h | 4 +++ 2 files changed, 81 insertions(+) diff --git a/fs/libfs.c b/fs/libfs.c index c297953db948..711eecc125bd 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -1776,6 +1776,83 @@ static const struct dentry_operations generic_ci_dentry_ops = { .d_revalidate = fscrypt_d_revalidate, #endif }; + +/** + * generic_ci_match() - Match a name (case-insensitively) with a dirent. + * This is a filesystem helper for comparison with directory entries. + * generic_ci_d_compare should be used in VFS' ->d_compare instead. + * + * @parent: Inode of the parent of the dirent under comparison + * @name: name under lookup. + * @folded_name: Optional pre-folded name under lookup + * @de_name: Dirent name. + * @de_name_len: dirent name length. + * + * Test whether a case-insensitive directory entry matches the filename + * being searched. If @folded_name is provided, it is used instead of + * recalculating the casefold of @name. + * + * Return: > 0 if the directory entry matches, 0 if it doesn't match, or + * < 0 on error. + */ +int generic_ci_match(const struct inode *parent, + const struct qstr *name, + const struct qstr *folded_name, + const u8 *de_name, u32 de_name_len) +{ + const struct super_block *sb = parent->i_sb; + const struct unicode_map *um = sb->s_encoding; + struct fscrypt_str decrypted_name = FSTR_INIT(NULL, de_name_len); + struct qstr dirent = QSTR_INIT(de_name, de_name_len); + int res = 0, match = 0; + + if (IS_ENCRYPTED(parent)) { + const struct fscrypt_str encrypted_name = + FSTR_INIT((u8 *) de_name, de_name_len); + + if (WARN_ON_ONCE(!fscrypt_has_encryption_key(parent))) + return -EINVAL; + + decrypted_name.name = kmalloc(de_name_len, GFP_KERNEL); + if (!decrypted_name.name) + return -ENOMEM; + res = fscrypt_fname_disk_to_usr(parent, 0, 0, &encrypted_name, + &decrypted_name); + if (res < 0) + goto out; + dirent.name = decrypted_name.name; + dirent.len = decrypted_name.len; + } + + /* + * Attempt a case-sensitive match first. It is cheaper and + * should cover most lookups, including all the sane + * applications that expect a case-sensitive filesystem. + */ + if (folded_name->name) { + if (dirent.len == folded_name->len && + !memcmp(folded_name->name, dirent.name, dirent.len)) { + match = 1; + goto out; + } + res = utf8_strncasecmp_folded(um, folded_name, &dirent); + } else { + if (dirent.len == name->len && + !memcmp(name->name, dirent.name, dirent.len) && + (!sb_has_strict_encoding(sb) || !utf8_validate(um, name))) { + match = 1; + goto out; + } + res = utf8_strncasecmp(um, name, &dirent); + } + +out: + kfree(decrypted_name.name); + if (res < 0) + return res; + return (match || !res); +} +EXPORT_SYMBOL(generic_ci_match); #endif #ifdef CONFIG_FS_ENCRYPTION diff --git a/include/linux/fs.h b/include/linux/fs.h index ff1338109b54..690b37e1db95 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3281,6 +3281,10 @@ extern int generic_file_fsync(struct file *, loff_t, loff_t, int); extern int generic_check_addressable(unsigned, u64); extern void generic_set_sb_d_ops(struct super_block *sb); +extern int generic_ci_match(const struct inode *parent, + const struct qstr *name, + const struct qstr *folded_name, + const u8 *de_name, u32 de_name_len); static inline bool sb_has_encoding(const struct super_block *sb) { -- 2.34.1
WARNING: multiple messages have this Message-ID (diff)
From: Eugen Hristev via Linux-f2fs-devel <linux-f2fs-devel@lists.sourceforge.net> To: tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, jaegeuk@kernel.org, chao@kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org Cc: krisman@suse.de, brauner@kernel.org, jack@suse.cz, linux-kernel@vger.kernel.org, eugen.hristev@collabora.com, viro@zeniv.linux.org.uk, kernel@collabora.com, Gabriel Krisman Bertazi <krisman@collabora.com> Subject: [f2fs-dev] [PATCH v14 3/9] libfs: Introduce case-insensitive string comparison helper Date: Wed, 20 Mar 2024 10:46:16 +0200 [thread overview] Message-ID: <20240320084622.46643-4-eugen.hristev@collabora.com> (raw) In-Reply-To: <20240320084622.46643-1-eugen.hristev@collabora.com> From: Gabriel Krisman Bertazi <krisman@collabora.com> generic_ci_match can be used by case-insensitive filesystems to compare strings under lookup with dirents in a case-insensitive way. This function is currently reimplemented by each filesystem supporting casefolding, so this reduces code duplication in filesystem-specific code. Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> [eugen.hristev@collabora.com: rework to first test the exact match] Signed-off-by: Eugen Hristev <eugen.hristev@collabora.com> --- fs/libfs.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/fs.h | 4 +++ 2 files changed, 81 insertions(+) diff --git a/fs/libfs.c b/fs/libfs.c index c297953db948..711eecc125bd 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -1776,6 +1776,83 @@ static const struct dentry_operations generic_ci_dentry_ops = { .d_revalidate = fscrypt_d_revalidate, #endif }; + +/** + * generic_ci_match() - Match a name (case-insensitively) with a dirent. + * This is a filesystem helper for comparison with directory entries. + * generic_ci_d_compare should be used in VFS' ->d_compare instead. + * + * @parent: Inode of the parent of the dirent under comparison + * @name: name under lookup. + * @folded_name: Optional pre-folded name under lookup + * @de_name: Dirent name. + * @de_name_len: dirent name length. + * + * Test whether a case-insensitive directory entry matches the filename + * being searched. If @folded_name is provided, it is used instead of + * recalculating the casefold of @name. + * + * Return: > 0 if the directory entry matches, 0 if it doesn't match, or + * < 0 on error. + */ +int generic_ci_match(const struct inode *parent, + const struct qstr *name, + const struct qstr *folded_name, + const u8 *de_name, u32 de_name_len) +{ + const struct super_block *sb = parent->i_sb; + const struct unicode_map *um = sb->s_encoding; + struct fscrypt_str decrypted_name = FSTR_INIT(NULL, de_name_len); + struct qstr dirent = QSTR_INIT(de_name, de_name_len); + int res = 0, match = 0; + + if (IS_ENCRYPTED(parent)) { + const struct fscrypt_str encrypted_name = + FSTR_INIT((u8 *) de_name, de_name_len); + + if (WARN_ON_ONCE(!fscrypt_has_encryption_key(parent))) + return -EINVAL; + + decrypted_name.name = kmalloc(de_name_len, GFP_KERNEL); + if (!decrypted_name.name) + return -ENOMEM; + res = fscrypt_fname_disk_to_usr(parent, 0, 0, &encrypted_name, + &decrypted_name); + if (res < 0) + goto out; + dirent.name = decrypted_name.name; + dirent.len = decrypted_name.len; + } + + /* + * Attempt a case-sensitive match first. It is cheaper and + * should cover most lookups, including all the sane + * applications that expect a case-sensitive filesystem. + */ + if (folded_name->name) { + if (dirent.len == folded_name->len && + !memcmp(folded_name->name, dirent.name, dirent.len)) { + match = 1; + goto out; + } + res = utf8_strncasecmp_folded(um, folded_name, &dirent); + } else { + if (dirent.len == name->len && + !memcmp(name->name, dirent.name, dirent.len) && + (!sb_has_strict_encoding(sb) || !utf8_validate(um, name))) { + match = 1; + goto out; + } + res = utf8_strncasecmp(um, name, &dirent); + } + +out: + kfree(decrypted_name.name); + if (res < 0) + return res; + return (match || !res); +} +EXPORT_SYMBOL(generic_ci_match); #endif #ifdef CONFIG_FS_ENCRYPTION diff --git a/include/linux/fs.h b/include/linux/fs.h index ff1338109b54..690b37e1db95 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3281,6 +3281,10 @@ extern int generic_file_fsync(struct file *, loff_t, loff_t, int); extern int generic_check_addressable(unsigned, u64); extern void generic_set_sb_d_ops(struct super_block *sb); +extern int generic_ci_match(const struct inode *parent, + const struct qstr *name, + const struct qstr *folded_name, + const u8 *de_name, u32 de_name_len); static inline bool sb_has_encoding(const struct super_block *sb) { -- 2.34.1 _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
next prev parent reply other threads:[~2024-03-20 8:46 UTC|newest] Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-03-20 8:46 [PATCH v14 0/9] Cache insensitive cleanup for ext4/f2fs Eugen Hristev 2024-03-20 8:46 ` [f2fs-dev] " Eugen Hristev via Linux-f2fs-devel 2024-03-20 8:46 ` [PATCH v14 1/9] ext4: Simplify the handling of cached insensitive names Eugen Hristev 2024-03-20 8:46 ` [f2fs-dev] " Eugen Hristev via Linux-f2fs-devel 2024-03-20 8:46 ` [PATCH v14 2/9] f2fs: " Eugen Hristev 2024-03-20 8:46 ` [f2fs-dev] " Eugen Hristev via Linux-f2fs-devel 2024-03-20 8:46 ` Eugen Hristev [this message] 2024-03-20 8:46 ` [f2fs-dev] [PATCH v14 3/9] libfs: Introduce case-insensitive string comparison helper Eugen Hristev via Linux-f2fs-devel 2024-03-20 8:46 ` [PATCH v14 4/9] ext4: Reuse generic_ci_match for ci comparisons Eugen Hristev 2024-03-20 8:46 ` [f2fs-dev] " Eugen Hristev via Linux-f2fs-devel 2024-03-20 8:46 ` [PATCH v14 5/9] f2fs: " Eugen Hristev 2024-03-20 8:46 ` [f2fs-dev] " Eugen Hristev via Linux-f2fs-devel 2024-03-20 8:46 ` [PATCH v14 6/9] ext4: Log error when lookup of encoded dentry fails Eugen Hristev 2024-03-20 8:46 ` [f2fs-dev] " Eugen Hristev via Linux-f2fs-devel 2024-03-20 8:46 ` [PATCH v14 7/9] f2fs: " Eugen Hristev 2024-03-20 8:46 ` [f2fs-dev] " Eugen Hristev via Linux-f2fs-devel 2024-03-22 22:11 ` Gabriel Krisman Bertazi 2024-03-22 22:11 ` [f2fs-dev] " Gabriel Krisman Bertazi 2024-03-20 8:46 ` [PATCH v14 8/9] ext4: Move CONFIG_UNICODE defguards into the code flow Eugen Hristev 2024-03-20 8:46 ` [f2fs-dev] " Eugen Hristev via Linux-f2fs-devel 2024-03-25 16:26 ` Gabriel Krisman Bertazi 2024-03-25 16:26 ` [f2fs-dev] " Gabriel Krisman Bertazi 2024-03-20 8:46 ` [PATCH v14 9/9] f2fs: " Eugen Hristev 2024-03-20 8:46 ` [f2fs-dev] " Eugen Hristev via Linux-f2fs-devel
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